Federal public defenders have been appointed to represent Dylann Roof in connection with the shooting deaths last week at an African-American church in South Carolina — an indication that federal charges could be filed in addition to nine state murder counts.

A U.S. magistrate’s judge in Charleston named two members of the public defender’s office to represent Roof this week, citing a separate investigation the Justice Department opened after the shootings at Emanuel African Methodist Episcopal Church. Roof, 21, hasn’t yet been charged with a federal crime, but U.S. Attorney General Loretta Lynch has said federal authorities are investigating the shootings as a possible hate crime.